Power system.



J. w. KIRKLAND.

POWER SYSTEM.

Patented May 16, 1911.

APPLICATION FILED SEPT. 27, 190B.

2 SHEETSSHEET 1.

g Q. I I

I m '7 10 E2 9 P Inventor:

John W.*Kirkland Witnesses:

J. W. KIRKLAND.

POWER SYSTEM.

APPLICATION FILED $119127, 1000.

992,209. Pitented May 16,1911.

2 SHEETS-SHEET 2.

Witnesses: Inventor:

John W.Kirkland,

' by W M- Q ILL PATENT OFFICE.

JOHN W. KIRKLAND,

OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

POWER SYSTEM.

Specification of Letters Patent.

Patented May 16, 1911.

Application filed September 27, 1909. Serial No. 519,802.

To all whom it may concern:

Be it known that I, JOHN W. KmKLAxn, a citizen of the United States, residing at Schenectady, in the county of Schenectady,

State of New York, have invented ccrtain new and useful Improvements in Power Systems, of which the following is a specification.

The present invention relates to power sys- 1 terns wherein high pressure prime movers exhaust into low pressure prime movers, the said prime movers driving independently variable loads.

More specifically my invention is directed to a system wherein a reciprocating engine drives one kind of a load, as for example the shafting in a factory, mill or other industrial concern, the exhaust from the en gine passing into and driving a low pressure turbine. On the shaft of the turbine is an electric generator used for lighting, poweror other purposes. It is evident that with such a system the loads on the engine and turbine may vary independently over wide ranges.

The object of my invention is to improve the economy of such a system.

For a consideration of what I believe to be novel and my invention, attention is directed to the accompanying description and claims appended thereto.

In the accompanying drawing, which is illustrative of my invention, Figure 1 is a diagrammatic view of a high-pressure engine andloW-pressure condensing turbine, and Fig. 2 is a view in side elevation of the low-pressure turbine.

1 indicates the cylinder of the engine and 2 its fly wheel, 3 the connecting rod and t '--the piston rod. The fly wheel is connected to the pulley 5 on the jack-shaft 6 or other power-consuming device by the belt 7. High pressure steam enters the engine by the pipe 8 under the control of suitable governing means, and the exhaust passes by the pipe 9 to the low pressure turbine 10. The exhaust from the'turbine passes to the surface or other condenser 11. On the shaft of the turbine is an electric generator 12, which maybe of the alternating or'direct current type. The exhaust steam for the turbine may be supplied by one or more high presi sure engines. When there is more than a single engine. in provided, into which the engines exhaust.

the system a header 13 is This header may supply one or more low pressure turbines.

The turbine I have elected to show is of the Curtis multi-stage type, but I do not wish to limit myself thereto, since other types of turbines may be employed. The turbine is divided into stages or regions having different pressures by suitable means, such as the diaphragms 1 1. In each compartment thus formed in the casing is a wheel having one, two or more rows of wheel buckets 15. \Vhcre two or more rows are employed intermediate buckets 16 are provided between each two rows. Steam or other motive fluid is admitted to the first stage by nozzles 17. Each diaphragm is provided with stage nozzles, passages or other devices 18 which convert, as do the admission nozzles, a certain amount of the pressure of the fluid into velocity and discharge it against the buckets. The wheels act to extract the energy from the motive fluid and transmit it to the shaft 19 in the form of rotary motion. Steam is admitted to the nozzles by the annular conduit or steam chest 20. The admission nozzles may extend wholly or partially around the machine, depending upon its character, output, etc. In the present case the nozzles surround the wheel, as do the stage nozzles and the machine is, therefm-e, of the total ilowtype, although as stated above, it may be of the partial [low type.

The main shaft 19 drives through suitable gearing a vertically disposed governor shaft contained in the casing 21. ()n the shaft is a speed governor of any well known type that is inclosed by thecasing 22. The movements of the governor weights are communicated to the rod 23 and the latter moves the free end of the governor lever 2ft up or down as the case may be. The governor lever controls the movements of the pilot valve 25 through the rod 26 and lever 27, and the valve controls the movements of the hydra n lic motor 28. The movements of the piston of the moto' are con'imunicated to the pilot valve by the lever 29, link 30 and lever 27, the parts 27, 29 and 30 forming a follow-up device to prevent overlravel 0 the motor piston in a manner well understood.

On the end of the piston rod is a rack 31 that meshes with a pinion 32 carried by the rock shaft 33, the latter being supported by bearings attached to the base of themachine. On this shaft are earns 34 and 35 which control the operation of by-pass valves 3t337 located in the conduit 38 that is connected to and extends from the steam chest to and is connected with the exhaust conduit 39. This conduit 38 is connected by passages such as 4:0 to one or more stages or regions of intermediate pressure and by the passage 40" to the conduit 39 and forms a low resistance shutnt path for the steam from the steam chest to said stages and to the exhausteonduit 39 of the turbine. The conduit 38 may be on the outside of. the turbine casing or within it, as desired. uThe pressure in the conduit 39 is the same as that of the condenser, disregarding any slight di'tference due to losses by friction.

It is evident that when the valves 36- 37 are closed (I have-shown two, but more or less can be provided depending upon conditions) all of the steam entering the steam chest must pass through the nozzles 17 and buckets of the turbine 'and perform useful work. Under these conditions the pressure in the chest will correspond to that'of the engine exhaust disregarding friction losses, and the turbine will give its full output, assuming the supply of steam from the engine 'or header to be suliicient. Assuming now that the load on the turbine decreases and that on the engine remains constant, theturbine will increase its speed. and the governor will move the pilot valve in a direction to cause the piston of the motor to move up, and in so doing rotate the cam 34 in a direction to open the valve 36 against its closing spring by an amount depending upon the speed change. This means that a-certain amount of steanrwill flow through the conduit 38 and'thc passage 40, thereby shunting the first stage. The amount of steam passing, and hence the effect of the shunt depends upon the valve opening. IV hen fully open virtually all of the steam will pass through the conduit 38. A certain relatively small amount will however flow through the 1102- zles and buckets and hold the turbine speed normal. The distribution'of steam will be determined by the relative resistances of the two paths.

Inasmuch as the pressure in the stage 41 I will be less than the pressure in the steam chest 20, due'to the increased area of the working passage for the .steam leading therefrom and to the efi'ectsof the condenser, it follows that the back pressure on the engine will bc-reduced when the valve 36 is open, and hence the efiiciency of the engine will be increased. Under these conditions there may be a very good vacuum existing in all of the piping back to the engine, in which case. the engine will act as a con- (lensing instead of as a non-condensing unit. Assuming a further decrease in load the sec none will. escape to the open air and be wasted.

Assuming that the engine supplies too much steam for the turbine, either because it 1s of larger capacity or any other reason, the valve mechanlsm of the turbine Wlll act in the same manner as described and the" amountof steam in excess of that required by the turbine will be shunted past one or more stages, finally doing Work in one or more stages on its way to the condenser.

An advantage of this arrangement resides;- 5 in the fact that fractional loads on the.

turbine are driven with lower. pressure steamthanv would be possible if the steam had to traverse the whole turbine, and hencesteam of lower pressure can be utilized. Further,

the 'back pressure exerted on the engine; at

these fractional loads is also decreased. I 3

1t is'unnecessary with my improvediar rangement in order to obtain good economy to closely proportion the load on the turbine to that carried by the engine, since a heavy load on the engine and a light loadon the turbine simply means that the initialpressure on the turbine will be reduced and the engine will have the benefit of partial vacuum in its exhaust. The normalfinal pressure of the reciprocating engine may be that of atmosphere, or it may be abovei'that ressure as desired. P a

I have used the terms high ressure and low pressure intheir relative sense,

meaning that one is higher than theother.

I have shown the conduit 38 connectedto the steam chest 20 and to the exhaust conduit 39 of the turbine, but the same'efi'ect will be obtained if the conduit is connected to the pi e leading to the steam chest. and to the pipe eading from the turbine to the con denser. The particular arrangement shown is, however, desirable, because 1t requires the minimum amount ofpiping and fittings.

In accordance-with the provisions of the patent statutes, I have described the principle of operation of my invention, together withthe apparatus which I'now consider to lll' represent the best embodiment thereof; but

I desire to have it understood that the ap paratus shown is only illustrative, andthat.

the invention can be carried out by other means. v q- \Vhat I claim as new and desire to secure by Letters Patent of the United States, is

1. In combination, a high pressure prime mover, a low pressure prime mover receiving the exhaustfrom the first, a conduit connected to the low pressure prime mover and which forms a. shunt therefor, a valve in the conduit which controls its connnnnication with a region of intermediate pressure in the low pressure prime mover, and a device responsive to speed changes of the low pressure prime mover for controlling the action of the valve.

2. In combination, a high pressure prime mover, a low pressure prime mover receiving the exhaust from the first, a conduit connected to the low )ressure prime mover and which forms a shunt therefor, valves in the conduit that control its communication with legions of different pressures within the low pressure prime mover, and means responsive to load changes for operating the valves.

3. In combination, a high pressure engine, a low pressure turbine, a conduit which is connected to the inlet of the turbine and to regions in the interior of the turbine having difl'erent pressures and forms a low re sistance shunt, valves controlling the passage of motive fluid through the conduit into said regions, and a speed responsive device driven by. the turbine for operating: the valves successively.

4. An elastic fluid turbine that is provided with rows of buckets arranged within a casing, a motive fluid chest and an exhaust con duit therefor, a conduit which is connected to regions Within the turbine casing having varying pressures and which forms a low resistance shunt path for the motive fluid, valve n'ieans controlling the distribution of motive fluid between the turbine and conduit, and a governor for the valve means which opens said means as the speed of the turbine increases.

An elastic fluid turbine comprising a rotor, a stator. a supply chest and an exhaust conduit, a conduit connected to the chest and to an intermwliatc pressure region of the turbine and also to the exhaust conduit, the said conduit forming a low resistance shunl from the point o'l admission to said region and to the exhaust of the turbine, valve means in the conduit, and a speed governor for controlling the opening and closing of the valve means.

6. .In combination, a multi-stage elastic fluid turbine, a source of motive fluid supply therefor, a conduit connected to the source and to different stages of the turbine, valves controlling the admission of iluid from the conduit to the stages, and a governing mechanisni acting on the valves to cut one stage of the turbine after another out of service as the load decreases beginning with the initial. stage.

7. In co'u'ibimition, a high pressure engine, a low pressure turbine receiving the exhaust from the engine, the engine and turbine driving il1(ll.[)Cl]l.llCllt-ly variable loads, a condenser tor the turbine, a conduit that is connected to the inlet and to exhaust of the turbine and also to a region of intermediate.

pressure therein, valve means in the conduit for cutting, portions of the turbine into and out of service as the load changes, thereby permitting the condenser to reduce the back pressure on the engine as the load on the turbine decreases, and a governor for said valve means that is sensitive to load changes .ot' the. turbine.

8. In combination, a high pressure prime mover, a low pressure turbine receiving exhaust from the prime mover, a condenser connected to the turbine, a conduit that is connected lo the inlet of the turbine. to the condenser, and al o to a region withinthe turbine whose pressure is intermediate that of the inlet and exhaust, a valve controlling the passage of lluid from the conduit to said region, a second valve that controls the passage of llnid from the conduit to the condenser. and means f r aetuating said valves.

in wilne -=s win-roof. l have hereunto set my hand this twenty sixth day of August,

ltltlil.

JOHN \V. KIRKLAND. \Vil nesscs Snixi-zv Hnl'ln, Tnos. (l. Miriam. 

